Guide pin for disc brake assembly and disc brake assembly including such a guide pin

Abstract

An improved guide pin structure adapted for use in a vehicle disc brake assembly comprises a first end including a head portion; a second end including an end face and a lead-in zone, the lead-in zone provided with a rounded generally bullet nose shaped radius adapted for insertion into an aperture of a component of the vehicle disc brake assembly; and a center section defining a shank having a slide surface, the center section defining a guide pin axis; wherein the bullet nose shaped radius of the lead-in zone includes an axial offset relative to the end face and a radial offset relative to the slide surface, and wherein the axial offset is larger than the radial offset by a ratio of at least 2 to 1.

1. A guide pin adapted for use in a vehicle disc brake assembly comprising:
 a first end including a head portion; 
 a second end including an end face and a lead-in zone, the lead-in zone provided with a rounded generally bullet nose shaped radius adapted for insertion into an aperture of a component of the vehicle disc brake assembly; and 
 a center section defining a shank having a slide surface, the center section defining a guide pin axis; 
 wherein the bullet nose shaped radius of the lead-in zone includes an axial offset relative to the end face and a radial offset relative to the slide surface, and wherein the axial offset is larger than the radial offset by a ratio of at least 2 to 1; 
 wherein the shank portion is provided with only two slots formed therein along a portion thereof; 
 wherein the two slots are arranged on the shank portion of the guide pin generally one-hundred and eighty degrees apart from each other; 
 wherein the slide surface is defined on the shank portion of the guide pin at least in an area defined between the two slots thereof; 
 wherein the first end of the guide pin further includes at least one indicia provided thereon; and 
 wherein the at least one indicia is arranged in alignment with at least one of the two slots of the shank portion in order to enable the guide pin to be installed in a guide pin bore provided in the vehicle disc brake assembly with the two slots of the shank portion oriented in a predetermined position in the guide pin bore such that a pair of reactive loads which are generated during brake actuation are applied only against the slide surface of the guide pin and are not applied against the two slots of the guide pin. 
 
     
     
       2. The guide pin of  claim 1  wherein a ratio of the axial offset to the radial offset is approximately 3 to 1. 
     
     
       3. The guide pin of  claim 1  wherein the first end includes a pair of indicia provided thereon, and wherein a respective one of the pair of indicia is aligned with a respective one of the two slots of the shank portion. 
     
     
       4. The guide pin of  claim 1  wherein the head portion defines a head axial length and the shank portion defines a shank diameter, and wherein the head axial length is not greater than approximately one half of the shank diameter. 
     
     
       5. The guide pin of  claim 4  wherein said head portion includes a threaded aperture. 
     
     
       6. A vehicle disc brake assembly comprising:
 a brake caliper; 
 a pair of brake pads carried by the disc brake assembly and adapted to be disposed on opposite axial sides of a brake rotor; 
 an actuator for selectively moving the brake pads into frictional engagement with the brake rotor; and 
 a pair of guide pins adapted to be secured to a fixed component for slidably supporting the brake caliper, at least one of the guide pins including a first end including a head portion, a second end including an end face and a lead-in zone, the lead-in zone provided with a rounded generally bullet nose shaped radius adapted for insertion into an aperture of a component of the vehicle disc brake assembly, and a center section defining a shank having a slide surface, the center section defining a guide pin axis, wherein the bullet nose shaped radius of the lead-in zone includes an axial offset relative to the end face and a radial offset relative to the slide surface, and wherein the axial offset is larger than the radial offset by a ratio of at least 2 to 1; 
 wherein the shank portion is provided with only two slots formed therein along a portion thereof; 
 wherein the two slots are arranged on the shank portion of the guide pin generally one-hundred and eighty degrees apart from each other; 
 wherein the slide surface is provided on the shank portion of the guide pin at least in an area defined between the two slots thereof; 
 wherein the first end of the guide pin further includes at least one indicia provided thereon; and 
 wherein the at least one indicia is arranged in alignment with at least one of the two slots of the shank portion in order to enable the guide pin to be installed in a guide pin bore provided in the vehicle disc brake assembly with the two slots of the shank portion oriented in a predetermined position in the guide pin bore such that a pair of reactive loads which are generated during brake actuation are applied only against the slide surface of the guide pin and are not applied against the two slots of the guide pin. 
 
     
     
       7. The vehicle disc brake assembly of  claim 6  wherein a ratio of the axial offset to the radial offset is approximately 3 to 1. 
     
     
       8. The vehicle disc brake assembly of  claim 6  wherein the first end includes a pair of indicia provided thereon, and wherein a respective one of the pair of indicia is aligned with a respective one of the two slots of the shank portion. 
     
     
       9. The vehicle disc brake assembly of  claim 6  wherein the head portion defines a head axial length and the shank portion defines a shank diameter, and wherein the head axial length is not greater than approximately one half of the shank diameter. 
     
     
       10. The vehicle disc brake assembly of  claim 9  wherein said head portion includes a threaded aperture. 
     
     
       11. A vehicle disc brake assembly comprising:
 a brake caliper; 
 a pair of brake pads carried by the disc brake assembly and adapted to be disposed on opposite sides of a brake rotor; 
 an actuator for selectively moving the brake pads into frictional engagement with the brake rotor; and 
 at least one guide pin adapted to be secured to a vehicle component for slidably supporting the brake caliper, the at least one of the guide pin including a first end including a head portion, a second end including an end face and a lead-in zone, and a center section defining a shank having a slide surface, the center section defining a guide pin axis; 
 wherein the shank portion is provided with only two slots formed therein along a portion thereof; 
 wherein the two slots are arranged on the shank portion of the guide pin generally one-hundred and eighty degrees apart from each other; 
 wherein the slide surface is provided on the shank portion of the guide pin at least in an area defined between the two slots thereof; 
 wherein the first end of the guide pin further includes at least one indicia provided thereon; and 
 wherein the at least one indicia is arranged in alignment with at least one of the two slots of the shank portion in order to enable the guide pin to be installed in a guide pin bore provided in the vehicle disc brake assembly with the two slots of the shank portion oriented in a predetermined position in the guide pin bore such that a pair of reactive loads which are generated during brake actuation are applied only against the slide surface of the guide pin and are not applied against the two slots of the guide pin. 
 
     
     
       12. The vehicle disc brake assembly of  claim 11  wherein the lead-in zone is provided with a rounded generally bullet nose shaped radius adapted for insertion into an aperture of a component of the vehicle disc brake assembly. 
     
     
       13. The vehicle disc brake assembly of  claim 11  wherein the first end includes a pair of indicia provided thereon, and wherein a respective one of the pair of indicia is aligned with a respective one of the two slots of the shank portion. 
     
     
       14. The vehicle disc brake assembly of  claim 11  wherein the head portion defines a head axial length and the shank portion defines a shank diameter, and wherein the head axial length is not greater than approximately one half of the shank diameter. 
     
     
       15. The vehicle disc brake assembly of  claim 13  wherein said head portion includes a threaded aperture. 
     
     
       16. The vehicle disc brake assembly of  claim 12  wherein the rounded shaped radius of the lead-in zone includes an axial offset relative to the end face and a radial offset relative to the slide surface, wherein the axial offset is larger than the radial offset by a ratio of at least 2 to 1.